A postsynaptic neuron has an RMP of -70mV and a typical threshold of -55mV. It has three presynaptic inputs-from neurons X, Y, and Z. Stimulation of neuron X causes the postsynaptic neuron to depolarize by 0.5 mV. When X and Y are stimulated simultaneously, the postsynaptic neuron depolarizes by 1 mV. If X fires 10 times and Y fires 10 times the result will be
A. threshold is reached and an AP is fired.
B. the membrane depolarizes.
C. many APs are fired.
D. presynaptic inhibition.
E. a subthreshold summation.
Answer: E
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